People with pale skin and red hair may need to worry about more than just sun exposure in relation to their increased risk of skin cancer, suggests a paper in Nature this week. Harmful ultraviolet (UV) rays are a notable driver of skin cancer, but observations in mice with red hair and fair skin traits uncover a UV-independent pathway that also increases the risk of melanoma. The study finds that the pigment that gives hair a red hue can contribute to melanoma formation.
Individuals with pale skin, red hair, freckles and an inability to tan often have trouble producing the black-brown pigment eumelanin and instead produce the red-yellow pigment pheomelanin, which has weak UV shielding capacity. David Fisher and colleagues find that it’s not just poor protection from UV rays in these individuals that increases the risk of melanoma. They report a high incidence of skin cancers in mice with red hair traits, even in the absence of known drivers of melanoma, including UV exposure. As this effect is not repeated in pigment-free albino mice, the authors infer that pheomelanin has carcinogenic effects. They suggest that the pigment contributes to melanoma development by causing oxidative damage to cells.
These data demonstrate that, although UV protection remains important, additional strategies may be required for optimal melanoma prevention.